1994 Toyota Corolla Good Cold But Shakes when Hot and durin

3rd week of headache and hair lose. Down 500 dollars and still not fixed. Got laid off and cannot afford more fixes that don’t resolve the problem. Please help. The follow has been proofread four times and is worded very carefully.

The car works fine when cold but when the car reaches normal temperature there is sputtering / shaking / pinging / unsteady power when the car is idle and while accelerating.

This started occurring after I replaced the distributor due to the car being able to crank but not start up (which fixed the problem – this was done by a mechanic a friend recommended - he forgot the dusk cover one time and then he left out one of the screws that goes on the distributor cap *_*). The shaking most noticeable when I accelerate.

No engine light or anything else shows up on my dash. The car does not die. When the engine is just warm, it wouldn’t make vibrations when I put it in neutral, but once the engine is hot after driving for 25 minutes, it shakes/sputters in drive, neutral, reverse, and park. It shakes the most when I have been traveling at high speed and come to a stoplight. Then the car will idle really rough. When the car is moving, I can feel the shaking the most when it begins a gear. I can’t tell if it goes away after the beginnings of the revs or if the car is moving so fast I don’t notice the uneven acceleration. Feels the same when going uphill. There is no shaking if my foot is off the gas pedal. I have changed the transmission fluid 50K miles ago but I did not change the transmission filter.

I want to say that its not getting fuel but I can’t tell if it’s the catalytic converter or timing belt or bad fuel. I thought about it being the transmission but I thought that if that were the case, why wouldn’t it shake in park while it is in the driveway and when the engine is cold? I also notice that there is a faint hissing sound coming out from my muffler. I notice the sound changes when I step on the gas. The sound of the hissing gets louder when I rev the car. I don’t think its due to a hole puncture as my muffler does not sound loud.

I had the whole distributor changed (as far as I can tell from the outside it looks brand now), changed the: ignition rotor, distributor cap, spark plugs, spark plug wires, PCV & hose, fuel filter, 02 oxygen sensor, cleaned the: Intake Manifold, Throttle Body, EGR, EGR hoses, air charge sensor (the one in the air filter box). Cleaned the Idle Air Control and tested it with a multimeter. Cleaned the throttle position sensor but did not know how to test it. Cleaned the Vehicle Speed and MAP Sensor with electronic parts cleaner but did not know how to test those either. I wanted to check fuel pressure but I don’t know how to do it. I installed a new fuel filter but it didn’t make a difference so I returned the new one and put the old one back on.

No fuel present in the hose that connects the fuel pressure regulator to the intake manifold after it has been running.

For the Idle Air Control, it seemed to be working properly as it opened up a lot more after I cleaned the carbon that was stuck at the bottom around of the metal door. I thought it was normal that it didn’t close all the way since it came to that position every time, whereas before the cleaning when I put it on the multimeter the door would open slowly. Now it opens and closes quickly.)

Things to mention:

Something I thought I mention is that when I changed the fuel pump, the fuel was open to air for an hour or so. And then I put a towel over the opening as I went inside to eat and then to AutoZone to go buy the new fuel pump. My brother told me that the fuel would only go back if I left it open to exposed air for days.

I also put Lucas Fuel Treatment into the tank before all of this occurred.

I opened my radiator cap and noticed there was orange coloring around the bottom of the cap and the water looks tinted orange. I’m not too sure if that was the color of the coolant from the previous owner or if the water is dirty.

Sometimes after traveling at high speed, if I put it into neutral it will stop idling rough. But usually it will just idle slightly bad rather than rough like it does in drive. Also, now and then when I put the car into neutral at the light, the idle will go up and down.

All this movement and unsteadiness seems to come from the front part of the car. But I cannot differentiate from the transmission area or the engine area as my 94 corolla is light and can move easily, even from cars passing by me.

I am sure the hoses to the fuel filter are on right and tight.

I’ve checked batter voltage, alternator, cylinder compression,

Although the acceleration is uneven, there is still power.

After all the changes the car is more powerful and zippy. I can hear the system breathing better. But vibration occurs.

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All give any informative as you want. I notice a lot of little things so if you have any detailed questions I would be glad to try to explain it to you or go to the car and find out.

The things I think are on the plate are timing belt? Coolant temp sensor? Catalytic converter? Did I get a faulty distributor? Please help.

Blessings,

Doyle